1. Field of the Invention
The present invention relates to a planet carrier mechanism. More specifically, the present invention relates to a planet carrier mechanism for a planetary gear set.
2. Background Information
A conventional planet carrier in a planetary gearset has a pair of members that has a plurality of planet gears sandwiched therebetween. The pair of members is, for example, disk-shaped plates that are disposed to be parallel to each other.
In the conventional planet carrier just described, the pair of members is fixed to each other by forming a plurality of bent parts that is bent in the axial direction on one of the members of the pair and forming holes in the other member of the pair. The tip of the bent parts are inserted into the holes and welded. The bent parts, which extend between the plurality of planet gears, are contrived so as not to interfere with the planet gears, a sun gear, and a ring gear.
Regarding the type of welding, electron beam welding is generally used because it causes little welding distortion and thus reduces the amount of after-processing required after welding. However, since even electron beam welding causes a slight amount of distortion, after-processing is required on a shaft hole section of a planetary pinion gear because the shaft hole section requires particularly high precision.
In view of the above, there exists a need for a planet carrier mechanism for a planetary gear set that overcomes the above-mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
An object of the present invention is to resolve the problems caused by welding during the manufacture of planet carrier mechanisms.
A planet carrier mechanism for a planetary gearset in accordance with a first aspect of the present invention meshes with a sun gear and a ring gear and can rotate about a central axis. The planet carrier mechanism is provided with a plurality of planet gears, a pair of carrier members, and a plurality of pin members. The pair of carrier members is disposed on both sides of the planet gears in an axial direction and rotatably support the planet gears. The plurality of pin members is disposed between the plurality of planet gears in the rotational direction of the planetary gearset and are fixed at both ends to the pair of carrier members by caulking.
In this planet carrier mechanism, the pair of carrier members is fixed together by the plurality of pin members. Both ends of each pin member are caulked to the carrier members. Consequently, welding is unnecessary and the problems associated with welding are resolved.
A planet carrier mechanism in accordance with a second aspect of the present invention is the mechanism of the first aspect, wherein a plurality of shafts is further provided for rotatably supporting the plurality of planet gears on the pair of carrier members. Both ends of the shafts are fixed to the pair of carrier members by caulking.
With this planet carrier mechanism, the plurality of pins and the plurality of shafts can be caulked simultaneously, thus reducing the number of manufacturing steps.
A planet carrier mechanism in accordance with a third embodiment of the present invention is the mechanism of the first or second aspects, wherein the pair of carrier members is a pair of plate members that are parallel to each other.
These and other objects, features, aspects, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.